• Current Photovoltaic Research
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• 제1권1호
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• pp.59-62
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• 2013

We investigated the effects of ZnO thin film deposition methods on the performance of inverted polymer solar cells with a structure of ITO/ZnO/P3HT:PCBM/MoO3/Al. The ZnO thin films were deposited by various methods (spin coating of nanoparticles, sol-gel process, atomic layer deposition) and their morphology was analyzed by atomic force microscopy (AFM). The device with ZnO nanoparticle thin films showed the highest power conversion efficiency of 3 % with low series resistance and high shunt resistance. The superior performance of the device with the ZnO nanoparticle layer is attributed to better electron extraction capability.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.76.1-76.1
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• 2013

Atomic Layer Deposition (ALD) has remarkably developed in semiconductor and nano-structure applications since early 1990. Now, the advantages of ALD process are well-known as controlling atomic-level-thickness, manipulating atomic-level-composition control, and depositing impurity-free films uniformly. These unique properties may accelerate ALD related industries and applications in various functional thin film markets. On the other hand, one of big markets, Display industry, just starts to look at the potential to adopt ALD functional films in emerging display applications, such as transparent and flexible displays. Unlike conventional ALD process strategies (good quality films and stable precursors at high deposition processes), recently major display industries have suggested the following requirements: large area equipment, reasonable throughput, low temperature process, and cost-effective functional precursors. In this talk, it will be mentioned some demands of display industries for applying ALD processes and/or functional films, in terms of emerging display technologies. In fact, the AMOLED (active matrix organic light emitting diode) Television markets are just starting at early 2013. There are a few possibilities and needs to be developing for AMOLED, Flexible and transparent Display markets. Moreover, some basic results will be shown to specify ALD display applications, including transparent conduction oxide, oxide semiconductor, passivation and barrier films.

• 반도체디스플레이기술학회지
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• 제9권2호
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• pp.91-96
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• 2010

In recent years there have been considerable attentions on nanoimprint lithography (NIL) by the display device and semiconductor industry due to its potential abilities that enable cost-effective and high-throughput nanofabrication. Although one of the current major research trends of NIL is large-area patterning, the technical difficulties to keep the uniformity of the residual layer become severer as the imprinting area increases more and more. In this paper we consider the roll-to-plate type imprinting process. In the process a glass mold, which is placed upon the 2nd generation TFT-LCD glass sized substrate(370${\yen}$470 mm), is rolled by a rubber roller to achieve a uniform residual layer. The pressure distribution on the glass mold by rolling of the rubber roller is crucial information to analyze mold deformation, transferred pattern quality, uniformity of residual layer and so forth. In this paper the quantitative pressure distribution induced by rolling of the rubber roller was calculated with finite element analysis under the assumption of Neo-Hookean hyperelastic constitutive relation. Additionally the numerical results were verified by the experiments.

• 반도체디스플레이기술학회지
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• 제18권4호
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• pp.96-99
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• 2019

Atomic layer etching (ALE) is one of the most promising techniques in the semiconductor industry. Since ALE has to be precisely controlled on the angstrom scale to achieve ideal results, an in-situ analysis of the processes is highly required. In this regard, we found during ALE experiments with in-situ monitoring with an ellipsometer that changes in the substrate temperature affected the refractive index of a material, leading to changes in measured film thickness. In addition, more ideal ALE results could be achieved by keeping the substrate temperature constant.

• 반도체디스플레이기술학회지
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• 제18권2호
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• pp.98-102
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• 2019

Direct plasma-enhanced atomic layer deposition (PEALD) are widely used for $SiO_2$ and SiON thin film process in current semiconductor industry. However, this exhibits poor step coverage for three-dimensional device structure due directionality of plasma species as well as plasma damage on the substrate. In this study, to overcome this issue, low temperature (< $300^{\circ}C$) $SiO_2$ and SiON thin film processes were studied using inductively coupled plasma (ICP) type remote PEALD with various reactant gases such as $O_2$, $H_2O$, $N_2$ and $NH_3$. It was confirmed that the interfacial properties such as fixed charge density and charge trapping behavior of thin films were considerably improved by hydrogen species in $H_2O$ and $NH_3$ plasma compared to the films grown with $O_2$ and $N_2$ plasma. Furthermore, the leakage current density of the thin films was suppressed for same reason.

• 한국분말재료학회지
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• 제30권2호
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• pp.156-168
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• 2023

The semiconductor industry faces physical limitations due to its top-down manufacturing processes. High cost of EUV equipment, time loss during tens or hundreds of photolithography steps, overlay, etch process errors, and contamination issues owing to photolithography still exist and may become more serious with the miniaturization of semiconductor devices. Therefore, a bottom-up approach is required to overcome these issues. The key technology that enables bottom-up semiconductor manufacturing is area-selective atomic layer deposition (ASALD). Here, various ASALD processes for elemental metals, such as Co, Cu, Ir, Ni, Pt, and Ru, are reviewed. Surface treatments using chemical species, such as self-assembled monolayers and small-molecule inhibitors, to control the hydrophilicity of the surface have been introduced. Finally, we discuss the future applications of metal ASALD processes.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.174-179
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• 2017

We designed the CMOS analog integrate and fire (I&F) neuron circuit for driving memristor based on resistive-switching random access memory (RRAM). And we fabricated the RRAM device that have $HfO_2$ switching layer using atomic layer deposition (ALD). The RRAM device has gradual set and reset characteristics. By spice modeling of the synaptic device, we performed circuit simulation of synaptic device and CMOS neuron circuit. The neuron circuit consists of a current mirror for spatial integration, a capacitor for temporal integration, two inverters for pulse generation, a refractory part, and finally a feedback part for learning of the RRAM. We emulated the spike-timing-dependent-plasticity (STDP) characteristic that is performed automatically by pre-synaptic pulse and feedback signal of the neuron circuit. By STDP characteristics, the synaptic weight, conductance of the RRAM, is changed without additional control circuit.

• 센서학회지
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• 제7권1호
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• pp.73-82
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• 1998

실리콘 표면 미세가공에 있어서, 새로 개발된 HF 기상식각 공정은 미소구조체들을 띄우는데 매우 효과적임을 입증하였다. 무수 불화수소와 메탄올을 이용한 기상식각 시스템에 대한 기능 및 특성을 기술하였고, 실리콘 미세구조체룰 띄우기 위한 회생층 산화막들의 선택적 식각특성이 고찰되었다. 구조체층으로는 인이 주입된 다결정실리콘이나 SOI 기판의 단결정실리콘을 사용하였다. 회생층으로는 TEOS 산화막, 열산화막, 저온산화막을 사용하였다. 기존 습식식각과 비교해 볼 때, 공정에 기인된 고착현강이나 잔류물질이 없는 미세구조체를 성공적으로 제작하였다.

• 반도체디스플레이기술학회지
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• 제17권4호
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• pp.66-69
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• 2018

This study was researched the electrical properties of semiconductor devices such as ITO, $SiO_2$, $V_2O_5$ thin films. The films of ITO, $SiO_2$, $V_2O_5$ were deposited by the rf magnetron sputtering system with mixed gases of oxygen and argon to generate the plasma. All samples were cleaned before deposition and prepared the metal electrodes to research the current-voltage properties. The electrical characteristics of semiconductors depends on the interface's properties at the junction. There are two kinds of junctions such as ohmic and schottky contacts in the semiconductors. In this study, the ITO thin film was shown the ohmic contact properties as the linear current-voltage curves, and the electrical characteristics of $SiO_2$ and $V_2O_5$ films were shown the non-linear current-voltage curves as the schottky contacts. It was confirmed that the electronic system with schottky contacts enhanced the electronic flow owing to the increment of efficiency and increased the conductivity. The schottky contact was only defined special characteristics at the semiconductor and the interface depletion layer at the junction made the schottky contact which has the effect of leakage current cutoff. Consequently the semiconductor device with shottky contact increased the electronic current flow, in spite of depletion of carriers.

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.15-18
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• 2022

The ultraviolet-C emitting praseodymium doped yttrium phosphate (YPO₄:Pr³⁺) powder was synthesized by conventional solid-state reaction. The electroluminescence device was fabricated by simple screen-printing method using the synthesized YPO₄:Pr³⁺ powder, especially, polyvinylidene fluoride as an insulating layer was applied on the printed YPO₄:Pr³⁺ powder for stable performance of the electroluminescence. The electroluminescence properties were investigated under alternating current power system of 400 Hz. The device starts to emit at 350 V, which showed the ultraviolet-C emission peaking at the 233, 245, 264, 273 nm attributed to electronic transition of the Pr³⁺ ions. The electroluminescence intensity was increased as increasing the operating voltage and the device revealed stable performance up to 600 V due to the polyvinylidene fluoride serve as a protective layer.